This invention relates to diffusing devices for controlling the flow and direction of air into a room from an air duct. More particularly, the invention relates to a linear slot diffuser that reduces rattle noise when the air is controlled as it flows in the room.
Air distribution devices, also referred to as diffusers, are typically set into the ceiling or other walls in a room and receive conditioned air along its length from a supply duct. These devices have elongated narrow slots, each of which is opened across its full width and enclosed by a frame. An extruded member which is within the slots and attached to the frame holds one or more vanes. The vanes are mounted to the support member with hinges or resistance so that their orientation may be altered to vary the direction of air flowing through the distribution device.
Examples of prior distribution devices are described in U.S. Pat. Nos. 3,126,811, 3,185,068 and 3,185,069 and in British Patent No. 1,514,459. Other examples of slot diffusers are manufactured by Titus Corp. of Richardson, Tex.; Metal Industries Inc. of Clearwater, Fla. and J and J, Inc. of El Paso, Tex. These patents and products all have the aforementioned features with structural differences present mainly in the shape of the frame or the vane.
The vanes, frames and support members of the prior art air distribution devices are constructed from metal to provide rigidity and stability when air flows through the device at a high rate. Stability is necessary to prevent a change in vane orientation while air is being directed at various angles into (or out of) the room. A drawback to these devices is that when air flows across the vane, the vane frequently vibrates because of the metal-to-metal contact between the vane and support member. The vibration may result in unwanted rattling. Another drawback to prior art devices is that this vibration may be propagated through the device to the support member to cause rattle.